The Data Coordinating Center (DCC) will collaborate with Clinical Centers, ancillary study sites, central laboratories and pathologist, and the National Institute of Diabetes and Digestive and Kidney Diseases project scientist to design and carry out the "Study of viral resistance to antiviral therapy of chronic hepatitis C." The DCC brings together substantive, methodological, analytic and managerial expertise from the University of Pittsburgh Graduate School of Public Health. The DCC will: a. Identify and compile background information regarding diagnosis and treatment for patients with hepatitis C infection b. In collaboration with other investigators, develop the study protocol c. Provide training and develop quality control procedures to assure consistent protocol implementation d. Develop computerized database e. Monitor ongoing progress of study f. Collect, edit, store, and manage data g. Analyze data and report study results h. Provide administrative support